pulley swap-04 cobra safe?

[robs1280]

probably a dumb question (because I see everyone with a 03-04 do it), but is swapping your stock pulley for a smaller pulley safe for the engine-I mean you obviuosly run more boost, i was just wondering what is the smallest pulley(boost you can run on the stock engine) you can run safely without harming the internals inside engine. Want to make swap, but I want to make sure my cobra runs well above 100,000 reliable miles. What pulley size? what is the safe boost range ( everyone knows the stock pulley is good for about 8 psi boost). thanks.

 

[TDS-03]

link to answers HERE

:beer:

 

[Screamin'SVT]

Yes a pulley swap is safe, but only with the proper tune. If you just throw a pulley on there, you will be pushing a lot more air through the motor (duh). Without a corresponding increase in fuel, you will run lean and blow up. So a pulley swap is safe as long as you get a dyno tune to get your A/F straight. As far as pulleys go, the smallest available is 2.76", which I believe is in the neighborhood of 14psi. Some people will argue that a smaller pulley overspins the blower (it does) and creates to much heat, but IMO it is as safe as a 2.93" or larger pulley.

 

[nightstalker865]

before everyone jumps down your neck. I will go ahead and tell you my thoughts on it. The stock pulley is a 3.65 the most popular upgrades would be 2.93 or a 2.80. these depending on other mods will put you in the 450-480rwhp range. boost is not what kills these engines they are iron blocks with forged internals they will hold what ever you throw at them. I think I have seen stock bottom ends hold up to 1000rwhp with the right tuning of course. getting a custom tune done for your mods is a must. there are several companys that can build you a custom tune and mail it to you. RTWD and Amazon seem to be the most popular. Making sure your timming and A/F ratio is right will help you make the most out of your mods and ensure a safe running motor. but i will warn you once you start modding you will no stop it's a bug and is very contagious

Eric

 

[Black2003Cobra]

Personally, I feel anything below 2.93" is where you need to start addressing other issues (besides just the chip or tune). For example, below that, you really run the risk of pegging the stock MAF, especially if you drive in cold winter weather. Not that this can't be fixed (with the SCT meter or mjchips Xtender), but you should be aware of that. And of course, yes, the faster you spin the blower, the hotter things get. You might also want to look into an aftermarket heat exchanger if you're going with a 2.8", for example. Oh, and the 2.8" will likely slip unless you add idlers. A 2.93" may or may not (w/o idlers) if it is the "non-slip" design. So part of the answer depends on how much (money) you want to put into it.

Also, keep in mind that the more stress you put on the engine, the shorter its life. I don't think there is a sudden "drop" in longevity if you're just playing around in the 2.8-3.2 range, (so long as you take the appropriate precautions), it'll just gradually be reduced, if you follow me. (Even at 2.8 or 2.93, you're already spinning the blower past the design max, BTW.)

 

[I-CAN-STANG]

link to answers HERE

:beer:

:nonono:

 

[Wings65288]

Lol

 

[sndmn_2000]

i would change the cooling system first before installing anything smaller than 2.93
the heat exchanger

 

[combatstang]

get a heat exchanger and u will be fine.. 2.8 will cause alot of heat.. but alot of power.. get the heatexchanger.. and u will run cooler than stock if u use the correct fluids...


Marc

 

[Snakebite2k3]

Sup guys I'm new here and about to buy an 03 snake but after reading
All this stuff about the pulley swapping being dangerous if u don’t know
What your doing I just want to ask if someone can help me round some
Numbers on how much rwhp I can expect by just adding CAI, Diablo Predator,
Cat Back and x pipe w/cats on stock pulley. Any help will be good. Thanks!!

 

[Sanchez209]

Pulley swap

Okay in just got 03 cobra and now I'm deciding to upgrade it to a. 2.76 pulley. I know I have to buy the idler pulley. My plan is to buy a bama tunner from american muscle and a belt too. My question is...do I have to upgrade my heat exchanger and injectors ?